which they aro composed; and that some of these strata 

 are (as with us) often red or ochi'eous. 



That this Avas the original construction of Auvergne, I i-est 

 upon the authority of Mr. Desmarest's own Memoir; where 

 the corresponding circumstances of the two countries are 

 detailed, in a manner not to be mistaken. For instance, 

 he tells us, page 706", that his prisms rest upon a stratum 

 of terres citifes, as our own often do upon an ochreous stra- 

 tum, strongly resembling baked earth, or brick. 



Page 730, he saj's, the strata fomi plusieurs etages, ou 

 ranges horizontales : and again, page 737, the same words 

 recur. Page 730, tei-races assez etendites, platforms and ter- 

 races, perpetually occur; and the perpendicular fapades, 

 common to all basaltic countries, are to be met with, as 

 well as his terres cuites, in almost every page. 



From this account of Mr. Desmarest, it is plain, that the 

 original materials and stratification, of Antrim and Auvergne, 

 were precisely similar: but we have had the good fortune to 

 remain undisturbed, while Auvergne has been ravaged by 

 destructive eruptions. One at Volvic, more tremendous 

 than the rest, poured forth vast torrents of lava ; while the 

 others, more diminutive, emitted only lighter materials, sco- 

 ria, cinders, pumices, and ashes.* 



Mr. Strange (whose adoption of Mr. Desmarest's theory 

 I have proved before, by a quotation from his geological 



letter 



*• These latter were, probably, some of the eruptions, to which Sidonius 

 Apollinaris was witness; while, in all likelihood, the great eruption of Volvic 

 happened at an earlier period. 



